Organic Light Emitting Diode (OLED) display devices are popular in the market because of their advantages such as bright colors, low power consumption, and small thickness. However, the development of OLED products is restricted due to reasons such as complex manufacturing process of OLED. Currently, the only widely used approach for manufacturing OLED devices is through evaporation. However, manufacturing the OLED devices through evaporation results in a very low utilization ratio of material, and accordingly, the cost of OLED products maintains high and the development of OLED products is influenced and restricted.
In conventional technologies, apparatuses and processes applying ink jet approach to manufacture OLED products are turning more and more mature nowadays and are getting widely used. Nearly no material is wasted when applying the ink jet approach to manufacture OLED products, but the following problem exists. When applying the ink jet approach to manufacture OLED products, the material needs to dissolve in a solvent to perform printing. During the printing process, the solvent in a pixel of a region closer to a periphery of a substrate volatizes more easily. A solvent atmosphere in a dummy region of the substrate differs from that in a center region of the substrate, the solvent in the center region of the substrate volatizes slowly while the solvent in the dummy region of the substrate volatizes quickly; hence, the dummy region of the substrate is apt to generate mura, which adversely influence the display effect.
Currently, in order to solve the problem that the mura is generated in the dummy region of the substrate and the display effect is adversely influenced, a common solution is to enlarge the dummy region of the substrate, but the width of the border increases due to the enlarging of the dummy region.